docs: def _filter_types(types_dict):
      # type: (Dict[FunctionKey, T]) -> Dict[FunctionKey, T]
      """Filter type info before dumping it to the file."""
  
      def exclude(k):
          # type: (FunctionKey) -> bool
          """Exclude filter"""
          return k.path.startswith('<') or k.func_name == '<module>'
  
      return {k: v for k, v in iteritems(types_dict) if not exclude(k)}